格氏栲天然林与人工林根系呼吸季节动态及影响因素  

Root respiration in a natural forest and two plantations in subtropical China: seasonal dynamics and controlling factors

作　　者：陈光水[1] 杨玉盛[1] 王小国[2] 谢锦升[2] 高人[1] 李震[2] 

机构地区：[1]福建师范大学亚热带资源与环境省重点实验室 [2]福建农林大学林学院,福州350002

出　　处：《生态学报》2005年第8期1941-1947,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(30300272;30170770);高等学校优秀青年教师教学科研奖励计划资助项目~~

摘　　要：通过用挖壕沟+静态碱吸收法对福建三明格氏栲天然林及33年生格氏栲和杉木人工林的根系呼吸进行为期2a定位研究.不同森林根系呼吸速率季节变化均呈单峰曲线,最大值出现在春末或夏初,最小值出现在冬季.1年中格氏栲天然林、格氏栲人工林和杉木人工林根系呼吸速率变化范围分别在157.76～480.40 mg CO2/(m2·h)、53.03～339.45 mg CO2/(m2·h)和16.66～228.02 mg CO2/(m2·h)之间.在近似正常气候状况的2002年,不同森林根系呼吸主要受土壤温度影响(R2=0.52～0.72);而土壤温度和土壤湿度共同则可解释根系呼吸速率季节变化的81%～90%.在极端干旱的2003年,根系呼吸受土壤温度或湿度的影响较小,土壤温度和土壤湿度共同仅能解释根系呼吸变化的24%～60%,这与根系在持续干旱期间长期处于近休眠状态有关.根系呼吸对土壤温度和土壤湿度的敏感性大小顺序均为杉木人工林>格氏栲人工林>格氏栲天然林.格氏栲天然林根系呼吸占土壤呼吸比例(47.6%)均高于格氏栲和杉木人工林的(42.5%和40.2%),不同森林根系呼吸占土壤呼吸比例均以冬季最低,而以5月或6月最高.格氏栲天然林、格氏栲人工林和杉木人工林根系呼吸年通量分别为6.537、4.013和1.828 tC/(m2·h).Tree root respiration is a primary contributor to the soil CO2 pool, and 2/3 of forest total soil respiration results from root respiration. Information about root respiration is useful for evaluating implications of environmental change on soil carbon cycling, carbon sequestration and developing carbon dynamic model in forest ecosystems. However, not until recent years that the researches on tree root respiration attracts the ecologists. The primary purpose of this study was to determine seasonal dynamics, controlling factors and inter stand difference of root respiration in a native forest of Castanopsis kawakamii （NF） and two plantations of Castanopsis kawakamii （CK） and Cunninghamia lanceolata （Chinese fir, CF） in sanming, Fujian, during a period of 2002-2003. Root respiration was separated from microbial respiration by trenching, and the rates were determined in situ utilizing the alkali sorption technique. Root respiration rates in the three forests showed a similar seasonal pattern with one single peak occurred during late spring or early summer and a minimum during dormant season, and varied from 157.76 to 480.40 mg CO2/（m^·h） in the NF, from 53.03 to 339.45 mg CO2/（m^2·h） in the CK, and from 16.66 to 228.02 mg CO2/（m^2· h） in the CF. In year 2002, a year representative of normal climate condition, root respiration was mainly controlled by soil temperature （at 5 cm depth） （R^2= 0. 52 - 0. 72）, and soil temperature and soil water content （at 0 - 10 cm depth） together could explain 81% - 90% of variation in root respiration. In year 2003, a year with extremely low rainfall during June to October, soil temperature and soil water content together could explain only 24% - 60% of variations in root respiration. The poor correlation of root respiration to soil temperature and soil water content together in year 2003 might be attributed to the acclimation mechanism of roots to the long dry season, during which root respiration remain in very low level similar to that in dorm

关 键 词：根系呼吸 土壤呼吸 土壤温度 土壤湿度 格氏栲 杉木 天然林 人工林 

分 类 号：Q945.19[生物学—植物学]